Frequency beam-steered substrate-integrated antennas

A method of forming an antenna, the method comprising:

• forming electrically-conductive vias that pass through a circuit substrate between a first electrically-conductive surface of the circuit substrate and a second electrically-conductive surface of the substrate;
• wherein the first electrically-conductive surface defines an upper surface of an electrically-conductive hollow or dielectric-filled waveguide;
• wherein the second electrically-conductive surface is parallel to the first electrically conductive surface and defines a lower surface of the waveguide;
• wherein the electrically-conductive vias define a first sidewall of the waveguide and a second sidewall of the waveguide that is opposite the first sidewall of the waveguide;
• wherein the electrically-conductive vias are configured and dimensioned to reflect incident RF signals having frequencies within a predetermined operational frequency range of the antenna such that the incident RF signals coupled to a first end of the waveguide are guided along a propagation direction of the waveguide toward a second end of the waveguide;
• wherein a width of the waveguide varies along the length of the waveguide and is defined by a variable distance between the first and second sidewalls along a second direction that is perpendicular to the propagation direction of the waveguide;
• and
• wherein the method further comprises:
• forming a plurality of groups of slotted openings distributed on the upper surface along the length of the waveguide that are configured to radiate a portion of the RF signals that travel along the propagation direction within the waveguide away from the waveguide;
• wherein each group of slotted openings comprises at least three slotted openings, and wherein a length of the slotted openings decreases in two directions outwards from a center of the group and wherein a length of the slotted openings decreases in two directions outwards from a center slotted opening of the group of slotted openings.

A waveguide antenna, comprising:

• a first electrically-conductive surface comprising a plurality of groups of slotted openings distributed on the upper surface along a length of the waveguide;
• wherein each group of slotted openings comprises at least three slotted openings, and wherein a length of the slotted openings decreases in two directions outwards from a center slotted opening of the group of slotted openings;
• wherein the length is along a first direction that defines a propagation direction for radio-frequency (RF) signals within the waveguide;
• and
• wherein a width of the waveguide is along a second direction that is perpendicular to the first direction.